Bone Metastasis of Breast Cancer: Molecular Mechanisms and Therapeutic Strategies

A microprotein encoded by LINC00263 promotes breast cancer osteolytic bone metastasis by inducing osteoclastogenesis and inhibiting osteoclast ferroptosis

Currently, there are no effective prevention or therapeutic methods for breast cancer bone metastasis (BC-BM), which leading to severe skeletal complications and increased mortality. Understanding the mechanisms underlying BC-BM could provide potential strategies for its prevention and treatment. In this study, we identified a new microprotein encoded by lncRNA LINC00263, which we named LINC00263-encoded protein (LINC00263-P), was significantly upregulated in bone metastatic breast cancer tissues and correlated with BC-BM. Overexpression of LINC00263 significantly promoted BC-BM, while treatment with the neutralizing anti-LINC00263-P antibody effectively inhibited BC-BM. Mechanically, the LINC00263-P binds to integrin αvβ3 for activating Src/Syk/Vav-3 axis and yes-associated protein 1 (YAP1) pathway, which enhanced osteoclastogenesis and diminishes ferroptosis in osteoclasts, thereby creating an osteolytic bone metastasis niche that fosters BC-BM. Importantly, treatment with angoroside C, an active component from the traditional Chinese medicine Scrophulariae Radix extract, effectively blocked the binding of LINC00263-P to αvβ3, thereby inhibiting abnormal osteoclastogenesis and preventing BC-BM. These findings highlight the crucial role of microprotein LINC00263-P in disrupting bone homeostasis and propose a potential molecular mechanism of BC-BM.

Comparative Effects of Turmeric Secondary Metabolites Across Resorptive Bone Diseases

Background: Turmeric (Curcuma longa L.) rhizomes, whose secondary metabolites include polyphenols and terpenoids, have been used medicinally for millennia. However, modern scientific inquiry has primarily focused on medicinal effects of turmeric's polyphenolic curcuminoids, including when evaluating turmeric use to maintain bone health. Methods: Disease-specific biological effects of turmeric's major secondary metabolites (polyphenols and/or terpenoids), with or without associated turmeric rhizome-derived polysaccharides, were determined in vivo using pre-clinical models of clinically relevant resorptive bone diseases induced by different mechanisms. These included inflammatory arthritis, cancer-driven osteolytic bone metastases, and hormone deficiency-driven post-menopausal osteoporosis. Results: In the arthritis model, the safety profile of curcuminoids alone was superior. However, curcuminoids and terpenoids each had anti-inflammatory effects and prevented bone resorption, with polysaccharide-containing curcuminoid extracts having greater effect than curcuminoids alone. In the human osteolytic breast cancer bone metastases model, curcuminoid extracts containing polysaccharides tended to yield greater effects in reducing bone osteolysis and tumor progression than curcuminoids alone or more complex extracts. In contrast, only purified curcuminoids prevented bone loss in a post-menopausal osteoporosis model, while polysaccharide-containing curcuminoid extracts were without effect. In vitro metabolite effects on disease-specific mechanistic pathways in synoviocytes, osteoclasts, or breast cancer cells were consistent with documented in vivo outcomes and included differential metabolite-specific effects. Conclusions: In summary, these findings suggest that turmeric's potential medicinal musculoskeletal effects are complex, pathway- and target-specific, and not limited to curcuminoids, with safety concerns potentially limiting certain uses.

Cancer metastasis: molecular mechanisms and therapeutic interventions

The metastatic cascade is a complicated process where cancer cells travel across multiple organs distant from their primary site of onset. Despite the wide acceptance of the 'seed and soil' theory, mechanisms driving metastasis organotropism remain mystery. Using breast cancer of different subtypes as the disease model, we characterized the 'metastatic profile of cancer cells' and the 'redox status of the organ microenvironment' as the primary determinants of cancer metastasis organotropism. Mechanically, we identified a positive correlation between cancer metabolic plasticity and stemness, and proposed oxidative stress as the selection power of cancer cells succeeding the metastasis cascade. Therapeutically, we proposed the use of pro-oxidative therapeutics in ablating cancer cells taking advantages of this fragile moment during metastasis. We comprehensively reviewed current pro-oxidative strategies for treating cancers that cover the first line chemo- and radio-therapies, approaches relying on naturally existing power including magnetic field, electric field, light and sound, nanoparticle-based anti-cancer composites obtained through artificial design, as well as cold atmospheric plasma as an innovative pro-oxidative multi-modal modality. We discussed possible combinations of pro-oxidative approaches with existing therapeutics in oncology prior to the forecast of future research directions. This paper identified the fundamental mechanics driving metastasis organotropism and proposed intervention strategies accordingly. Insights provided here may offer clues for the design of innovative solutions that may open a new paradigm for cancer treatment.

The Expression Profile of the RANK/RANKL/OPG Pathway in Breast Cancer Stem Cells Isolated From Breast Cancer Cell Lines

The RANK/RANKL/OPG signaling pathway plays a crucial role in breast cancer progression and metastasis. However, its expression patterns and potential implications in breast cancer stem cells remain poorly understood. This study aimed to characterize the expression profile of this pathway in breast cancer stem cells isolated from two distinct breast cancer cell lines: MDA-MB-231 and MCF-7. Mammospheres (MS), representing breast cancer stem cells, were generated using agar-coated 6 well tissue culture plates in suitable mammospheres culture conditions. Flow cytometric analysis showed enrichment of the CD44+/CD24- subpopulations in the mammospheres cultures, with MDA-MB-231 exhibiting a higher percentage compared to MCF-7. The isolated MS from both cell lines showed upregulation of stemness markers OCT4 and SOX2, with MS. MDA-MB-231 demonstrating higher expression levels. Analysis of the RANK/RANKL/OPG axis revealed differential expression patterns between the two cell lines. RANK expression was significantly upregulated in MS. MDA-MB-231 but not in MS. MCF-7. Interestingly, while OPG mRNA levels were elevated in mammospheres from both cell lines, secreted OPG protein levels were paradoxically reduced in the mammospheres conditioned media. Additionally, RUNX2, an osteoblastic marker, and a downstream target of RANK signaling, showed a decreased expression in both mammospheres compared to adherent cells. These findings suggest a complex, context-dependent regulation of the RANK/RANKL/OPG pathway in breast cancer stem cells, potentially contributing to the aggressive nature and metastatic propensity of triple-negative breast cancer. This study provides novel insights into the molecular characteristics of breast cancer stem cells and underscores the complexity of OPG/RANK/RANKL axis expression in them; a role yet to be fully elucidated.

The Potent Antioxidant 3,5-Dihydroxy-4-Methoxybenzyl Alcohol Reveals Anticancer Activity by Targeting Several Signaling Pathways in Bone Metastatic Human Breast Cancer MDA-MB-231 Cells

Human breast cancer is the leading cause of cancer-related death in women. Bone metastatic human breast cancer MDA-MB-231 cells are triple negative. The novel marine factor 3,5-dihydroxy-4-methoxybenzyl alcohol (DHMBA), a potent antioxidant, has been shown to prevent oxidative stress by scavenging free radicals in cells. This study investigates the effects of DHMBA on MDA-MB-231 cells in vitro. MDA-MB-231 cells were cultured with DHMBA (0.1-100 μM). DHMBA blocked the growth and stimulated the death of MDA-MB-231 cells, resulting in reduced cell numbers. DHMBA treatment decreased PI3-kinase 100α, Akt, MAPK, phosphor-MAPK, and mTOR and increased p53, p21, and Rb, which are suppressors in cell growth. DHMBA inhibited metastatic activity, including adhesion and migration of MDA-MB-231 cells. Coculture with MDA-MB-231 cells resulted in decreased growth and stimulated death of osteoblastic MC3T3-E1 cells and macrophage RAW264.7 cells, suggesting that cancer cells affect the bone microenvironment. Production of TNF-α, which is the mediator in the bone microenvironment, in MDA-MB-231 cells was inhibited by DHMBA treatment. Crosstalk between cancer cells and cells in the bone microenvironment was blocked by culture with DHMBA. DHMBA may inhibit the activity of triple-negative human breast cancer cells, providing a useful tool for the treatment of breast cancer.

Cannabinoid Receptor Type 2 Agonist, GW405833, Reduced the Impacts of MDA-MB-231 Breast Cancer Cells on Bone Cells

AIM

Breast cancer frequently metastasizes to bones. The interaction between breast cancer cells and bone cells results in osteolytic lesions by disrupting the balance between osteoblast-mediated bone production and osteoclast-mediated bone resorption. This study aims to investigate the effects of the cannabinoid receptor type 2 (CB2) agonist, GW405833, on interactions between breast cancer cells and osteoblasts as well as its impact on breast cancer-induced osteoclastogenesis.

MATERIALS & METHODS

MDA-MB-231, UMR-106, RAW 264.7 cells were used to represent breast cancer cells, osteoblast-like cells and macrophage-osteoclast precursor cells, respectively. Cell viability was evaluated by MTT assay, and breast cancer cell invasion was assessed by Transwell invasion assay. Tartrate-resistant acid phosphatase (TRAP) staining was utilized to evaluate osteoclastogenesis.

RESULTS

Our results demonstrated that GW405833 disrupted MDA-MB-231-induced UMR-106 cell death and promoted UMR-106 cell viability. The underlying mechanism of these effects was determined in this study. GW405833 reduced AKT phosphorylation in MDA-MB-231 cells without affecting mTOR protein expression or its phosphorylation. Conversely, in UMR-106 cells, GW405833 induced AKT and mTOR phosphorylated protein. Furthermore, the mTOR inhibitor reversed the GW405833-induced recovery of UMR-106 cell viability under MDA-MB-231-derived conditioned media (CM) exposure. These findings underscore the critical role of the AKT/mTOR pathway in mediating GW405833's inhibitory effects on cancer-bone interactions. Additionally, GW405833 suppressed osteoblast-enhanced breast cancer cell invasion and the expression of invasion-related proteins in both cell types, along with reducing osteoclastogenic factors induced by MDA-MB-231 CM in UMR-106 cells and suppressing MDA-MB-231 CM-enhanced osteoclastogenesis in RAW 264.7 cells.

CONCLUSION

This study highlights the therapeutic potential of cannabinoid receptor agonist for treating breast cancer bone metastasis and bone-related complications.

A water-soluble aggregation-induced emission luminogen for NIR-I/NIR-II fluorescence imaging of breast cancer bone metastases

Advanced breast cancer is prone to bone metastasis, which is the most common bone metastatic tumor. Current clinical methods for diagnosing breast cancer bone metastases rely on serological markers, computed tomography and magnetic resonance imaging. However, these technologies cannot meet patients' needs due to the delayed screening, complex procedures and expensive equipment. Optical imaging currently exhibits inexhaustible and vigorous vitality in the field of diagnosis thanks to its advantages of simplicity, good controllability and high resolution. Nevertheless, the development of prominent chromophores for the diagnosis of breast cancer bone metastases is an appealing yet significantly challenging task. In this contribution, we rationally designed and synthesized three water-soluble aggregation-induced emission (AIE) luminogens, named PEGTPA-BTD, PEGTPA-NTD, and PEGTPA-NSD, by introducing different moieties as electron acceptors and PEGylated triphenylamine derivatives as electron donors and hydrophilic moieties. In vitro experiments showed that PEGTPA-NSD has a longer absorption and emission wavelength, where the emission wavelength can extend into NIR-II region. Besides, PEGTPA-NSD could self-assemble into stable nanoparticles in aqueous solution. Cell experiments showed that PEGTPA-NSD had no obvious dark toxicity to tumor cells or normal cells, and were easily taken in by tumor cells for cell imaging. What's more, PEGTPA-NSD NPs possessed excellent fluorescence imaging performance and biocompatibility in vivo for breast cancer bone metastases in NIR-I and NIR-II region, respectively. In summary, PEGTPA-NSD is the first reported aggregation-induced emission luminogens (AIEgens) that can self-assemble to nanoparticles in aqueous solution for NIR-I/NIR-II fluorescence imaging of breast cancer bone metastases. These findings would provide new strategies for optical diagnostic imaging of breast cancer bone metastases to better advance clinical technology development.

Overexpression of RGPR-p117 reveals anticancer effects by regulating multiple signaling pathways in bone metastatic human breast cancer MDA-MB-231 cells

The role of RGPR-p117, a transcription factor, which binds to the TTGGC motif in the promoter region of the regucalcin gene, in cell regulation remains to be investigated. This study elucidated whether RGPR-p117 regulates the activity of triple-negative human breast cancer MDA-MB-231 cells in vitro. The wild-type and RGPR-p117-overexpressing cancer cells were cultured in DMEM supplemented with fetal bovine serum. RGPR-p117 overexpression suppressed colony formation and growth of cancer cells. Stimulatory effects of epidermal growth factor on cell growth were blocked by RGPR-p117 overexpression. Wild-type cell proliferation was repressed by cell cycle and intracellular signaling inhibitors. These effects were not potentiated in transfectants. Overexpressed RGPR-p117 protected cancer cells against apoptosis inducers. Mechanistic results showed that RGPR-p117 overexpression decreased the expression of Ras, PI3-kinase, Akt, mitogen-activated protein kinase, and mTOR, which are involved in cell growth, while it elevated the levels of the cancer cell suppressor p53, Rb, p21, and regucalcin. Overexpression of RGPR-p117 suppressed cancer cell migration and adhesion. Interestingly, osteoblastic MC3T3-E1 cells or macrophage RAW264.7 cells involved in the bone microenvironment were impaired by coculture with MDA-MB-231 cells. The effects of cancer cells were blocked by transfection. Coculture with conditioned medium obtained from breast cancer cells repressed proliferation and enhanced the death of osteoblastic cells and macrophages. A TNF-α signaling inhibitor blocked these effects. Thus, overexpressed RGPR-p117 was found to suppress the activity of breast cancer cells by regulating various signaling processes, providing new insight into cellular signaling regulation.

Liu-Shen-Wan inhibits PI3K/Akt and TRPV1 signaling alleviating bone cancer pain in rats

Patients with advanced-stage cancers often suffer from severe pain caused by bone metastasis and destruction, for which effective treatment options are limited. Liu-Shen-Wan (LSW) is a widely recognized herbal formula utilized for pain relief. This study aims to elucidate the effects of LSW on bone cancer pain (BCP). In this study, the pharmacology of LSW on BCP was screened by network pharmacology. A BCP model was conducted using Walker 256 cells. Paw withdrawal threshold and paw withdrawal latency were employed as measures to assess the pain threshold in rats. The pathways and cell types of LSW against BCP were explored. Next, the impact of LSW on Walker 256 cells was evaluated, and UPLC-MS was utilized to identify the active ingredients of LSW. Furthermore, the effects of the key active ingredient, Bufalin, on the BCP rats were evaluated. There were 275 shared targets between LSW and BCP, which were enriched in neural tissue ligand-receptor interaction pathway. LSW increased pain threshold and decreased inflammatory cytokines levels in BCP rats by inhibiting PI3K/Akt and transient receptor potential vanilloid 1 (TRPV1) signaling through astrocytes and microglia. LY294002 further alleviated BCP in rats, while the effects were reversed after treatment with insulin-like growth factor 1 (IGF-1). Both LSW and its active ingredient Bufalin were shown to inhibit the viability and migration of Walker 256 cells and induce apoptosis. Bufalin appears to be the key active ingredient of LSW and exerts its pain-relieving effects by suppressing PI3K/Akt and TRPV1 signaling in BCP.

A 3D-Printable Cell Array for In Vitro Breast Cancer Modeling

Breast cancer is the most common cancer and the second leading cause of cancer-related death in women. In advanced stages of the disease, breast cancer can spread and metastasize to the bone, contributing to malignant progression. The roles of tissue stiffness and remodeling of the tumor microenvironment are relevant in influencing cancer progression and invasiveness, but they are still poorly understood. In this study, we aimed to investigate the effect of bone tissue stiffness on breast cancer cell behavior, using 3D cell-biomaterial systems to model the in vivo conditions. For this purpose, we developed a 3D-printable cell array, which is a tunable and reproducible platform on small scale, where each compartment could mimic the physiological cancer environment with a shape and rigidity close to bone tissue. In this system, we observed that in the highly metastatic breast cancer line MDA-MB-231, embedded in PEG-silk fibroin (PSF) hydrogel spheres in the array's cavities, increasing stiffness promotes trans-differentiation into osteoblast-like cells and the production of breast microcalcifications. Moreover, we also tested this 3D model as a platform to evaluate the cell response to the therapy, in particular, investigating the drug sensitivity of the cancer cells to chemotherapeutics, observing a decrease in drug resistance over time in the array.

Pilot study on the in-vitro effect of radiation therapy on bending stiffness of intramedullary photodynamic implants

Photodynamic implants are an increasingly popular minimally invasive option for the surgical treatment of metastatic bone disease. Following surgery, adjuvant radiation therapy (RT) is frequently administered to achieve better disease control and improve patient quality of life, but the role of RT in implant failures associated with photodynamic implants remains unclear. The aim of this study is to determine if the therapeutic RT range of 10-50 Gy affects the biomechanical properties of photodynamic implants. For the experimental group, 15 photodynamic implants were divided evenly into 5 groups that were exposed to different doses of RT (10, 20, 30, 40 and 50 Gy). The control group consisted of 14 non-irradiated photodynamic implants. Four-point bending tests were conducted on all implants to determine bending stiffness. One-way ANOVA was conducted. Bending stiffness (N/mm) mean ± standard deviation for the non-irradiated control group was 38.0 ± 1.2. Bending stiffness (N/mm) mean ± standard deviation for the irradiated experimental groups was 39.2 ± 1.0. No significant difference was found between any groups. RT doses at a range of 10-50 Gy do not affect the bending stiffness of photodynamic implants. The yield and ultimate failure loads were 263.4 ± 5.2 (N) and 305.9 ± 5.5 (N) in the non-irradiated group vs. 266.8 ± 6.4 (N) and 306.8 ± 6.4 (N) in the irradiated group, respectively. The lack of statistical significance in the difference in stiffness, yield, and ultimate load properties among the groups means that it is less likely that RT at the evaluated doses contributes to intrinsic implant failure. Further studies need to be conducted to conclude the potential effect of RT on other mechanical properties of photodynamic implants.

Harnessing curcumin and nanotechnology for enhanced treatment of breast cancer bone metastasis

Breast cancer (BC) bone metastasis poses a significant clinical challenge due to its impact on patient prognosis and quality of life. Curcumin (CUR), a natural polyphenol compound found in turmeric, has shown potential in cancer therapy due to its anti-inflammatory, antioxidant, and anticancer properties. However, its metabolic instability and hydrophobicity have hindered its clinical applications, leading to a short plasma half-life, poor absorption, and low bioavailability. To enhance the drug-like properties of CUR, nanotechnology-based delivery strategies have been employed, utilizing polymeric, lipidic, and inorganic nanoparticles (NPs). These approaches have effectively overcome CUR's inherent limitations by enhancing its stability and cellular bioavailability both in vitro and in vivo. Moreover, targeting molecules with high selectivity towards bone metastasized breast cancer cells can be used for site specific delivery of curcumin. Alendronate (ALN), a bone-seeking bisphosphonate, is one such moiety with high selectivity towards bone and thus can be effectively used for targeted delivery of curcumin loaded nanocarriers. This review will detail the process of bone metastasis in BC, elucidate the mechanism of action of CUR, and assess the efficacy of nanotechnology-based strategies for CUR delivery. Specifically, it will focus on how these strategies enhance CUR's stability and improve targeted delivery approaches in the treatment of BC bone metastasis.

A Rare Cause of Nuchal Rigidity: Metastatic Triple-Negative Breast Cancer Involving the Skull and Upper Cervical Spine

A 48-year-old female presented to the ED with worsening headache and neck pain for the past week. Her medical history is significant for recurrent left-sided triple-negative breast cancer (TNBC) with metastasis to the chest wall, liver, and lungs, initially diagnosed two years ago. She underwent a left-sided mastectomy and received radiation therapy and chemotherapy. Physical examination was remarkable for nuchal rigidity and photophobia. MRI of the brain with contrast was performed, and the results were consistent with the new calvarium, skull, and upper cervical spine osseous metastases without any intracranial metastatic disease. This case report presents a rare cause of nuchal rigidity and photophobia due to an uncommon metastatic pattern in a patient with TNBC.

Tumor-on-chip platforms for breast cancer continuum concept modeling

Our previous article entitled "Proteomics and its applications in breast cancer", proposed a Breast Cancer Continuum Concept (BCCC), including a Breast Cancer Cell Continuum Concept as well as a Breast Cancer Proteomic Continuum Concept. Breast cancer-on-chip (BCoC), breast cancer liquid biopsy-on-chip (BCLBoC), and breast cancer metastasis-on-chip (BCMoC) models successfully recapitulate and reproduce in vitro the principal mechanisms and events involved in BCCC. Thus, BCoC, BCLBoC, and BCMoC platforms allow for multiple cell lines co-cultivation to reproduce BC hallmark features, recapitulating cell proliferation, cell-to-cell communication, BC cell-stromal crosstalk and stromal activation, effects of local microenvironmental conditions on BC progression, invasion/epithelial-mesenchymal transition (EMT)/migration, intravasation, dissemination through blood and lymphatic circulation, extravasation, distant tissues colonization, and immune escape of cancer cells. Moreover, tumor-on-chip platforms are used for studying the efficacy and toxicity of chemotherapeutic drugs/nano-drugs or nutraceuticals. Therefore, the aim of this review is to summarize and analyse the main bio-medical roles of on-chip platforms that can be used as powerful tools to study the metastatic cascade in BC. As future direction, integration of tumor-on-chip platforms and proteomics-based specific approaches can offer important cues about molecular profile of the metastatic cascade, alowing for novel biomarker discovery. Novel microfluidics-based platforms integrating specific proteomic landscape of human milk, urine, and saliva could be useful for early and non-invasive BC detection. Also, risk-on-chip models may improve BC risk assessment and prevention based on the identification of biomarkers of risk. Moreover, multi-organ-on-chip systems integrating patient-derived BC cells and patient-derived scaffolds have a great potential to study BC at integrative level, due to the systemic nature of BC, for personalized and precision medicine. We also emphasized the strengths and weaknesses of BCoC and BCMoC platforms.

Multi-level Percutaneous Vertebroplasty for Multiple Spinal Metastases With Asymptomatic Epidural Compression: A Case-Based Example of Minimally Invasive Patient Management

Percutaneous vertebroplasty (PVP) is a minimally invasive procedure that allows for treating or preventing vertebral fractures resulting from trauma, osteoporosis, or oncological conditions. Metastatic spinal disease is a condition that necessitates mostly palliative care and pain management with minimal invasiveness. It could present with axial or localized back pain and may be associated with neurological deficit if compression of the spinal cord and/or the nerve roots is involved. The treatment of such patients may present a challenge and is usually accomplished with open surgery and instrumentation. However, the potential perioperative complications of invasive surgical procedures may significantly worsen the quality of life in patients with an already poor prognosis. This case report presents minimally invasive management of multiple spinal metastases of the lumbar region in a 65-year-old female patient. She had a history of breast cancer and presented only with axial pain in the lumbar region and no neurological deficit. We performed a biopsy at the L3 level and multi-level PVP at the Th12-L5 levels; her pain diminished significantly, and she was mobilized later on the day of the surgery with a lumbar orthosis brace. Postoperative radiographic evaluation showed satisfactory cement distribution. The patient was subsequently referred to radiotherapy according to the decision of the multidisciplinary oncological committee.

Hydroxyapatite Film with Distinctive Roughness for Simulating the Bone Microenvironment and Revealing the Behavior of Metastatic Mammary Cancer

Breast cancer is a common malignant tumor arising in normal mammary epithelial tissues. Nearly 75% of the patients with advanced mammary cancer develop bone metastases, resulting in secondary tumor growth, osteolytic bone degradation, and poor prognosis. The bone matrix comprises a highly hierarchical architecture and is composed of a nonmineral organic part, a predominantly type-I collagen, and a mineral inorganic part composed of hydroxyapatite (HA) nanocrystals (Ca10(PO4)6(OH)2). Although there has been extensive research indicating that the material properties of bone minerals affect metastatic breast cancer, it remains unclear how the microenvironment of the bone matrix, such as the roughness, which changes as a result of osteolytic bone remodeling, affects this disease. In this study, we created HA coatings in situ on polyelectrolyte multilayers (PEMs) by incubating PEMs in a mixture of phosphate and calcium ions. The HA films with distinctive roughness were successfully collected by controlling the incubation time, which served as the simulated microenvironment of the bone matrix. MDA-MB231 breast cancer cells were cultured on HA films, and an optimal roughness was observed in the adhesion, proliferation, and expression of two cytokines closely related to bone metastasis. This study contributed to the understanding of the effect of the microenvironment of the bone matrix, such as the roughness, on the metastasis behavior of breast cancer.

Intra-bone marrow injection with engineered Lactococcus lactis for the treatment of metastatic tumors: Primary report

Bone marrow has the capacity to produce different types of immune cells, such as natural killer cells, macrophages, dendritic cells (DCs) and T cells. Improving the activation of immune cells in the bone marrow can enhance the therapy of bone metastases. Previously, we designed an engineered probiotic Lactococcus lactis, capable of expressing a fusion protein of Fms-like tyrosine kinase 3 ligand and co-stimulator OX40 ligand (FOLactis), and proved that it can induce the activation and differentiation of several immune cells. In this research, we successfully establish mouse models of bone metastasis, lung metastasis and intraperitoneal dissemination, and we are the first to directly inject the probiotics into the bone marrow to inhibit tumor growth. We observe that injecting FOLactis into the bone marrow of mice can better regulate the immune microenvironment of tumor-bearing mice, resulting in a tumor-suppressive effect. Compared to subcutaneous (s.c.) injection, intra-bone marrow (IBM) injection is more effective in increasing mature DCs and CD8+ T cells and prolonging the survival of tumor-bearing mice. Our results confirm that IBM injection of FOLactis reprograms the immune microenvironment of bone marrow and has remarkable effectiveness in various metastatic tumor models.

UDP-6-glucose dehydrogenase in hormonally responsive breast cancers

Survival for metastatic breast cancer is low and thus, continued efforts to treat and prevent metastatic progression are critical. Estrogen is shown to promote aggressive phenotypes in multiple cancer models irrespective of estrogen receptor (ER) status. Similarly, UDP-Glucose 6-dehydrogenase (UGDH) a ubiquitously expressed enzyme involved in extracellular matrix precursors, as well as hormone processing increases migratory and invasive properties in cancer models. While the role of UGDH in cellular migration is defined, how it intersects with and impacts hormone signaling pathways associated with tumor progression in metastatic breast cancer has not been explored. Here we demonstrate that UGDH knockdown blunts estrogen-induced tumorigenic phenotypes (migration and colony formation) in ER+ and ER- breast cancer in vitro. Knockdown of UGDH also inhibits extravasation of ER- breast cancer ex vivo, primary tumor growth and animal survival in vivo in both ER+ and ER- breast cancer. We also use single cell RNA-sequencing to demonstrate that our findings translate to a human breast cancer clinical specimen. Our findings support the role of estrogen and UGDH in breast cancer progression provide a foundation for future studies to evaluate the role of UGDH in therapeutic resistance to improve outcomes and survival for breast cancer patients.

Clinical practice guidelines for full-cycle standardized management of bone health in breast cancer patients

Bone health management for breast cancer spans the entire cycle of patient care, including the prevention and treatment of bone loss caused by early breast cancer treatment, the adjuvant application of bone-modifying agents to improve prognosis, and the diagnosis and treatment of advanced bone metastases. Making good bone health management means formulating appropriate treatment strategies and dealing with adverse drug reactions, and will help to improve patients' quality of life and survival rates. The Breast Cancer Expert Committee of the National Cancer Center for Quality Control organized relevant experts to conduct an in-depth discussion on the full-cycle management of breast cancer bone health based on evidence-based medicine, and put forward reasonable suggestions to guide clinicians to better deal with health issues in bone health clinics.

Cell-cell communication characteristics in breast cancer metastasis

Breast cancer, a highly fatal disease due to its tendency to metastasize, is the most prevalent form of malignant tumors among women worldwide. Numerous studies indicate that breast cancer exhibits a unique predilection for metastasis to specific organs including the bone, liver, lung, and brain. However, different types of, The understanding of the heterogeneity of metastatic breast cancer has notably improved with the recent advances in high-throughput sequencing techniques. Focusing on the modification in the microenvironment of the metastatic organs and the crosstalk between tumor cells and in situ cells, noteworthy research points include the identification of two distinct modes of tumor growth in bone metastases, the influence of type II pneumocyte on lung metastases, the paradoxical role of Kupffer cells in liver metastases, and the breakthrough of the blood-brain barrier (BBB) breach in brain metastases. Overall, this review provides a comprehensive overview of the characteristics of breast cancer metastases, shedding light on the pivotal roles of immune and resident cells in the development of distinct metastatic foci.

Thymus-derived hormonal and cellular control of cancer

The thymus gland is a central lymphoid organ in which developing T cell precursors, known as thymocytes, undergo differentiation into distinct type of mature T cells, ultimately migrating to the periphery where they exert specialized effector functions and orchestrate the immune responses against tumor cells, pathogens and self-antigens. The mechanisms supporting intrathymic T cell differentiation are pleiotropically regulated by thymic peptide hormones and cytokines produced by stromal cells in the thymic microenvironment and developing thymocytes. Interestingly, in the same way as T cells, thymic hormones (herein exemplified by thymosin, thymulin and thymopoietin), can circulate to impact immune cells and other cellular components in the periphery. Evidence on how thymic function influences tumor cell biology and response of patients with cancer to therapies remains unsatisfactory, although there has been some improvement in the knowledge provided by recent studies. Herein, we summarize research progression in the field of thymus-mediated immunoendocrine control of cancer, providing insights into how manipulation of the thymic microenvironment can influence treatment outcomes, including clinical responses and adverse effects of therapies. We review data obtained from clinical and preclinical cancer research to evidence the complexity of immunoendocrine interactions underpinning anti-tumor immunity.

Molecular imaging of bone metastasis

Recent advances in molecularly targeted modular designs for in vivo imaging applications has thrusted open possibilities of investigating deep molecular interactions non-invasively and dynamically. The shifting landscape of biomarker concentration and cellular interactions throughout pathological progression requires quick adaptation of imaging agents and detection modalities for accurate readouts. The synergy of state of art instrumentation with molecularly targeted molecules is resulting in more precise, accurate and reproducible data sets, which is facilitating investigation of several novel questions. Small molecules, peptides, antibodies and nanoparticles are some of the commonly used molecular targeting vectors that can be applied for imaging as well as therapy. The field of theranostics, which encompasses joint application of therapy and imaging, is successfully leveraging the multifunctional use of these biomolecules [[1], [2]]. Sensitive detection of cancerous lesions and accurate assessment of treatment response has been transformative for patient management. Particularly, since bone metastasis is one of the dominant causes of morbidity and mortality in cancer patients, imaging can be hugely impactful in this patient population. The intent of this review is to highlight the utility of molecular positron emission tomography (PET) imaging in the context of prostate and breast bone metastatic cancer, and multiple myeloma. Furthermore, comparisons are drawn with traditionally utilized bone scans (skeletal scintigraphy). Both these modalities can be synergistic or complementary for assessing lytic- and blastic- bone lesions.

How has the field of metastatic breast cancer in bones evolved over the past 22 years?

Background

Although knowledge on metastatic breast cancer in bones (MBCB) has increased rapidly over the past 22 years, a comprehensive and objective bibliometric analysis is still lacking.

Materials and methods

We used R, VOSviewer, and Citespace software to conduct a bibliometric analysis of 5,497 papers on MBCB from the Web of Science Core Collection (WOSCC) using author, institution, country/region, citation, and keyword indicators.

Results

A general strong sense of scholarly collaboration was noted in the MBCB field at the author, research institution, and country/region levels. We discovered some outstanding authors and highly productive institutions, but with less collaboration with other academic groups. Unbalanced and uncoordinated developments were observed among countries/regions in the field of MBCB research. We also found that by using various indicators and applying different analysis methods to them, we were able to broadly identify primary clinical practices, relevant clinical experiments, and directions for bioinformatics regarding MBCB, changes over the past 22 years, and current challenges in the field. The development of knowledge on MBCB is progressing greatly; however, MBCB is still incurable.

Conclusion

This study is the first to use bibliometrics to provide an overall analysis of the scientific output of MBCB studies. Palliative therapies for MBCB are mostly in a mature state. However, research on the molecular mechanisms and immune response to tumors related to the development of treatments to cure MBCB remains relatively immature. Therefore, further research should be undertaken in this area.